Transcript Cocaine and Reward Learning

COCAINE NEURAL
MECHANISM
And It’s Connection
To Reward Learning
What does cocaine do to your brain?
The Neural Basis of Cocaine’s Effect
• Cocaine is considered one of the most harmful and addictive
illegal drugs.
• Understanding physiological mechanisms of drug use can
help with treatment and prevention.
• The Pathological Learning Model: addictive drugs highjack
reward-learning mechanisms in the brain.
Reward Learning Circuit:
The Basics
Reward Learning Circuit:
The Basics
 Our brains are wired to learn
about potentially rewarding
stimuli.
Reward Learning Circuit:
The Basics
 Our brains are wired to learn
about potentially rewarding
stimuli.
 Dopamine (DA) is an important
neurotransmitter in this system.
Reward Learning
• Synaptic Strength – relative ability of neurons to pass on information
• Pre-synaptic – more/less neurotransmitter released
• Post-synaptic – changes in receptor expression
• Synaptic Plasticity – change in synaptic strength.
• Foundation of Memory Formation
Cocaine Neural Mechanism
• Cocaine acts on neurons of the reward circuit:
• DA Transporter Blockade
Cocaine Neural Mechanism
• Cocaine acts on neurons of the reward circuit:
• DA Transporter Blockade
• User learns to associate cocaine with rewarding feeling.
Cocaine Neural Mechanism
• Cocaine acts on neurons of the reward circuit:
• DA Transporter Blockade
• User learns to associate cocaine with rewarding feeling.
• Prolonged use correlated with internalization of some DA
receptors
Cocaine Neural Mechanism
• Cocaine acts on neurons of the reward circuit:
• DA Transporter Blockade
• User learns to associate cocaine with rewarding feeling.
• Prolonged use correlated with internalization of some DA
receptors
• Leads to a feedback loop of cocaine use and receptor
internalization.
Cocaine and Reward Learning:
Compare and Contrast
• Similarities
• Differences
The Pathological Learning Model: drug use usurps rewardmediating plasticity related to adaptive reward learning.
In-class activity
• The “What’s On My Back?” Game